Torque controlled mechanism



Nov; 23, 1943; R. s. TAYLOR TORQUE CONTROLLED MECHANIS j Original FiledD06. 3. 1937 Sheets-Sheet 1 INVENTOR 20B T 5- T YL 12 BY j Hi5 ATTORNEYAYLOR Nov. 23, 1943,

INVENTOR 12055 T 5. mw. 2 mg ATTORN EY R. S. TAYLOR TORQUE CONTROLLEDMECHANISM Original Filed Dec. 3, 1937 Nov. 23,

5 Sheets-Sheet 3 INVENTOR EOBE' Y H N R 0 U A D H Patented Nov. 23, 1943 UNITED V STATES PATENT OFFICE TORQUE CONTROLLED MECHANISM Roberts.Taylor, Seattle, Wash. Original application December a, 1937, Serial No.177,902, now Patent No. 2,244,133, datedJun'e 3, 1941. Divided and thisapplication September 17, 1940, Serial No. 357,141

Claims. (Cl. 188134) This appli ation is a division of my copendingapplication, Serial No. 177,902, filed December 3, 1937, and issued onJune 3, 1941, as Patent No. 2,244,133.

My invention relates to mechanism actuated in response to torque; andmore particularly to such mechanism operating in conjunction with aspeed change system.

It is among the objects of my invention to provide torque controlledmeans for changing the speed ratio in a transmission gearing.

Another object is to provid improved mechanism for effecting the speedchange when torque.

reaches a predetermined value.

Further objects include the provisionof torque means for actuatingpositively engageable elements, such as toothed brake or clutchelements; and the provision of such means for synchronizmg theengagement of the elements.

The invention possesses other objects and fea-' tures of advantage, someof which, with the foregoing, willfbe set forth in the followingdescription of my invention. It is to be understood that I do not limitmyself to this'disglosure of species of my invention, as I may adoptvariant embodimerits thereof within the scope ofthe claims.

Referring to the drawings:

Figure 1 is an axial sectional view showing a transmission embodying theimprovements of my invention. q 7

Figure 2 is a transverse vertical sectional view of the transmission,taken in a plane indicated by the line 2-2 of Figure 1, and showing theoneway clutch between the parts of the planetary gear system.

Figure 3 is a transverse vertical sectional view,

. taken in a plane indicated by the line 3--3 of Figure l, and showingthe torque controlled brake mechanism. 7

Figure 4 isv another transverse verticalsectional view, taken in a planeindicated by the line fl-t of Figure .1, and showing the ratchetsbetween the brake elements.

Figure 5 is a fragmentary axial sectional view of the transmission,showing the torque controlled brak in its engaged position.

Figures 6 and! are fragmentarysectional views, taken in a planeindicated by line 6-5 of Figure 3,

and showing the torque controlled brake togg es in extended andcollapsed positions, respectively.

Figure 8 is an axial sectional view of an underdrive transmissionembodying my invention.

In terms of broad inclusion, the mechanism of my inventioncomprises apair of engageable elemovement between the elements. Means are alsoprovided for synchronizing'engagement of the elements. As embodied in anoverdrivetransmission having a planetary gear system my mechanismcomprises a brake for holding a part of the systemagainst rotation; andas embodied in an underdrive transmission the mechanism com prises aclutch for locking the system together for rotation as a unit. a

In greater detail, and referring to Figures 1 to 7 of the drawings, anoverdrive transmission embodyingthe torque controlled mechanism of myinvention is contained in a housing adapted to be interposed in thetorque tube of an automobile, and preferablycomprising an intermediatesection 2 fastened to endsections 3 and 4 by suitable studs and bolts '6and 1. The end sections are formed with neck adapted to be connectedwith the end portions 8 of the torque tube. While the transmission isshown interposed in a torque tube behind the ordinary speed changetransmission. it is understood that the unit may be incorporated in. thedrive train ahead of the ordinary transmission.

and are connected to driving and driven sections l4 and I6 of thepropeller shaft by suitable sleeves l1 and I8. Driven sleeve 18 alsopreferably carries the speedometer gear l9, and an oil retaining ring 2|is preferably interposedbetween the sleeve and housing.

A planetary gear system is arranged in the housing and comprises anorbit or ring gear 22 splined in a cup-shaped rotor 23 formed on the endof driven shaft II. The planet pinion 24 of the planetary system isjournaled on a shaft 25 carried by a spider 21 splined on th inner endof drive shaft 9. A plurality, say three, of these planet pinions areprovided. The hub of spider 21 is preferably journaled in the recessedend of rotor 23, and suitable bearing rings are provided between theseparts.

The sun gear 29 of the planetary system is mounted on the inner end of asleeve 3| journaled on drive shaft'i-l on suitable bearings 30. By thisments, and torquemeans for controlling relative arrangement of theplanetary gears a speed increase or overdrive is provided when the sungear is held against rotation, as will be readily understood. If the sungear is not held the planetary system is of course ineifective, sincethe sun gear will merely spin freely.

A one-way clutch is interposed between parts of the planetary gearsystem, preferably between .by the one-way clutch rollers 35. clutchmember is shifted back however, the clutch the orbit and sun gears. Forthis purpose a pair of overrunning clutch rings 32 and 33 ar provided,separated by a bearing 34; the Outer ring 32 being splined in orbit;gear rotor 23 and the inner ring being splined on sun gear sleeve 3|. Aseries of clutch rollers 35 are arranged between the rings, and areurged counterclockwise as viewed in Figure 2 by a spring turned cage 36.In this normal position of the rollers the latter are wedged between theclutch rings by the inclined faces on the inner ring.

This looks the sun gear to the orbit gear when the sun gear tends torotate clockwise, but leaves the sun gear free to spin counterclockwiseif it is not otherwise held, Therefore, in the position of the partsshown in Figure 1, clockwise rotation of the drive shaft results in theplanet gears tending to rotate the sun gear clockwise relative totheorbit gear; all references to clockwise and counterclockwise rotationbeing taken as viewed from the left in Figure 1. But relative clockwiserotation of the sun gear is prevented by the oneway clutch rollers.35,so that the planetary system is locked for unitary rotation. As aresult,

the drive and driven shafts are connected toether for direct drive. I

This condition is maintained as long as the drive shaft tends to overrunthe driven shaft. When the driven shaft tends tooverrun the drive shafthowever, the planet pinions turn the sun gear counterclockwise, which itis free to do. Thus the driven shaft is free to overrun the drive shaft,giving the ordinary free-wheeling principle.

Means are also provided for optionally locking the sun gear to the orbitgear so that they are positively. fixed for unitary rotation. For thispurpose a clutch member 31 is slidably splined on sun gear sleeve 31,and is shiftable by a yoke -38 slidably mounted on pin 39. ,The yoke ismoved by an eccentric cam 41 turned by a crank 42 connected to asuitable lever in the drivers compartment by a' connecting rod 43. Inthe position of the clutch member shown in Figure 1 the sun gear is freeto rotate, except as limited When the teeth 44 are engaged with teeth 46on ring 32,

. thus positively locking the sun and orbit gears together in eitherdirection of rotation of the sun gear. This looks out the one-way clutchin I event freewheeling is not desired.

Also, positive clutching of the parts together permits the car to beplaced in reverse, and when my transmission is located behind theordinary transmission a suitable connection is made between theregularshifting mechanism and connecting rod 43 so that clutch member 31is always shifted back when the car is put in reverse. In other words;member 31 is optionally shiftable at the will of the driver, but isalways moved back by the act of putting the car in reverse. Of course ifmy transmission is located ahead of the ordinary speed changetransmission the shifting back of clutch member 31 when the car is. putin reverse is not necessary, because then the rotation of the driveshaft is always clockwise,

The mechanism to which my invention particu larly relates is a torquecontrolled brake for holding the sun gear against rotation tooperatively connect the shafts together through the overdrive gearing.The brake mechanism is supported by an annular ring or fixed reactorelement 41 bolted between sections 2 and 4 of the housing; the brakeoperating to releasably lock the sun element 48 and are adapted toengage the latter through an annular series of teeth 54 on the platescapable of meshing a complementary series of teeth 56 on opposite sidesof the central brake ring. Plates 53 are adapted to move toward and awayfrom each other to engage and disengage the central brake ring, and arealso capable of a limited degree of turning movement. The plates areconnected by a plurality of pins or bolts 51 extending through notches58 in the fixed element. These notches limit turning movement of theplates, and blocks 59 are provided on several of the pins for slidablyengaging the notches. See Figure 3.

The inner ends of ins 51 project beyond the inside plate and each has aspring 60 compressed between the end of the pin and plate. These springsserve to press the plates together, tending to engage the latter withthecentral brake ring 48. A series of pivoted arms 6| are interposedbetween the fixed element 41 and plates 53. These arms are preferably inthe nature of round nosed pieces arranged in pairs on opposite sides ofthe fixed element and seated in socketsprovided in the fixed element andplates. By this arrangement the pairs of pivoted arms 6| function astoggles; the arms of which are movable between extended and retractedposition upon relative turning movement between plates 53 and fixedelement 41. I

When the brake plates 53 are rotated clockwise to the limit of rotationin this direction permitted by pins 51 in notches 58, the toggle arms 6!are moved to extended positions to spread plates 53 out of engagementwith the central brake element 48, This opening of the toggles toextended positions is of course resisted by springs 60. Figures 1 and 6show the relationship between the parts when the toggles are extended.

When the brake plates are rotated counterclockwise to the limit ofrotation in the opposite direction permitted by pin 51 in notches 58,the toggle arms 61 are retracted or collapsed to bring plates 53together and into engagement with the central brake element 48. Figures5 and 7 show the parts with the toggles collapsed. It will be noted thatplates 53 close with a combined inward and turning motion, due to theaction of pivoted arms 6|. This particular movement insures a positiveand smooth engagement of the clutch teeth 54 and 56.

By this arrangement it is seen that plates 53 will spread to disengagethe brake when the clockwise torque of the central brake element 48 issufilcient to overcome the resistance which springs 68 offer to theopening of the toggles. It is to'be noted that'the toothed brakeelements operate to positively hold the sun gear until the precise timewhen the torque becomes great enough to open the toggles. Prior toopening there is no slippage, and once the critical torque is reachedthe brake disengages quickly. It is also to be noted that the relativelysmall angle which arms 6| make with elements 41 and 51 in the retractedposition offers a large initial resistance to opening movement, but thisresistance de-- creases as the arms extend, since the effective teeth'66 formed in the central element 48.

lever arms increase as arms 6| move out. To

insure complete opening of the toggles after the opening movement hasonce started, a plurality of springs 62 are preferably provided to bearagainst blocks 59. These springs urge the plates clockwise and functionto snap the toggles into final open positions. Adjusting screws 63 areprovided for altering the compression of these springs; which crews areheld in a selected position of adjustment by spring-pressed ballsengaging grooves in the screw heads as shown in Figure 3. V

Rotation of brake plates 53 counterclockwise, for the purpose ofcollapsing the toggles to engage the brake, is also derived fromrotation of the central brake element 48. As shown in Figures l and 4, aseries of one-way engaging devices or ratchets 64' are mounted on theinner peripheries of the brake plates for engaging ratchet The ratchetsare pressed by light springs 67; and the ratchet teeth are formed topermit free'rotation of brak element 48 clockwise, but to turn plates 53with element 48 whenthe latter tends to rotate counterclockwise.

It will be noted that brake elements 53 are turning with central brakeelement 48 'at the time of engagement. This turning of the brakeelements in the same direction, together with the combined inward andturning motion of brake elements 53 due to the toggle action, insuresperfect synchronization of the engaging parts.

Two of the blocks 59 are preferably provided with plug-like projections68 for seating in sockets 69 provided in fixed element 41, so that theplugs enter the sockets and serve as cushioning means to quiet the stopwhen the transmission changes from overdrive to direct.

The operation of the torquecontrolled brake is as follows: Consider thatthe optionally shiftable clutch member 31 is at the left to lock centralelement. 88 with the sun gear, and also consider that plates 53 of thereleasable brake are open. Under these conditions, the parts of theplanetary system are locked together for direct drive by the one-wayclutch rollers 35 so long as the toggles is greatest at the start anddecreases rapidly as the toggles spread apart. This insures that anyforce suflicient to start the toggles opening is ample to complete thebrake release motion.

The releasable brake is designed to keep the car in overdrive until thetorque of the sun gear exceeds a predetermined value. This brakereleasing torque is calculated to cut out the overdrive before the loadon the motor becomes too great. When the torque controlled brakereleases the sun gear the shafts are immediately connected for directdrive by the one-way clutch rollers 35, because at this time the driveshaft is tending to overrun the driven shaft. The direct drive will thenbe maintained until such time as the driven shaft again tends to overrunthe drive shaft, providing of course that the manually controlled clutchmember 31 remains in its forward position of engagement with the torquecontrolled brake unit. As long as the torque controlled brake is inoperation the driver may put the car in, overdrive at anytime byreleasing the throttle and then pressing in and letting out the regularfoot clutch pedal. The effort of the car wheels to speed up the motorwill then force the sun gear counterclockwise to collapse the togglesand engage brakeplates 53.

Means are provided for locking the shafts together through theoverdrive. As shown in Figure 3, a slidable block 8| is arranged in thefixed element 41, and is adapted to be interposed between one of theblocks 59 and the end of its notch. Block 81 is normally up out of theway (as seen in Figure 3), but may be brought down when blocks 59 areback in the collapsed position of the toggles. Movement ofv block 8! iscontrolled by a shaft 82 journaled in the fixed element and having aneccentrically disposed pin 83 engaging the block so that the latter ismoved in and out when the shaft is rotated by a crank 84 connected to asuitable knob or lever in the driver's compartment. A spring 86 behindthe block assists the drive shaft tends to overrun the driven shaft(which condition obtains under driving load). At this time the centralbrake element 48.merely turns clockwise, which it is free to do sinceratchets 68 do not prevent it.

However, when the driven shaft tends to overrun the drive shaft (whichcondition obtains under coasting load), the sun gear tends to runcounterclockwise. This turns the brake plates 53 counterclockwisethrough ratchets 68, thus collapsing toggles 6| to engage the brakeplates and lock the sun gear to the fixed element. With the sun gearlocked against rotation the pinions 28 planetate about it, causing theorbit gear to rotate faster than the drive shaft. One-way clutch rollers35 do not interfere with such relative rotation since its outer ring 32is free to overrun the inner ring 33. The shafts are thus connectedtogether through the planetary overdrive.

' This overdrive connection will'be maintained as longas the brakeplates 53 remain engaged. The torque of the sun gear of course istransmitted from central clutch I element 58 to the and open thetoggles.

the toggles is relatively small and great force is 'latters inwardmovement when crank 84 is rotated. 4 v

The transmission of my invention therefore provides means for cuttingthe overdrive gearing into and out of the drive train; depending uponthe rotational relationship and torque conditions between the shafts.The mechanism also permits the operator to optionally lock the shaftsfor direct drive; or connect them for direct drive with free-wheeling;or connect them through the torque controlled overdrive; or look themtogether Y through the overdrive.

Indicating means may be provided if desired for showing when thetransmission is in either direct or overdrive. Such indicating means maycomprise any suitable signaling circuit for energizing a lamp on thedashboard, preferably controlled by a spring pressed pin 81 on housing 2 andengageable with one of the brake plates 53.

If desired, the bolts 51 which connect the brake plates 53 may becentrally positioned so that the bolts project out an equal distancefrom each of the plates, and springs arranged on both ends of the bolts.This would reduce the length 'of springs 68 and also provide a morebalanced required to open them against spring 68. It will be observedthat the force required to open the unit.

While I have shown my torque mechanism as a brake in an overdrivegearing, it is understood that the mechanism may operate as a clutchsuch as provided in an underdrive gearing. In the latter case, as shownin Figure 8, the orbit gear 9| is connected to the drive shaft 92 andthe planet pinion 93 to the driven shaft 94. In this instead of being afixed element, is mounted for rotation with the orbit gear. With thiscombination, the load is first picked up and carried through the directdrive until the load releases the torque controlled clutch. Then theone-way brake locks the sun gear to give, the underdrive. Thisunderdrive relationship is then maintained until the driven shaft tendsto overrun the drive shaft, at which time the torque controlled clutchis again engaged to lock the gearing in direct.

When operating either as a brake or as a clutch my torque mechanism hastheadvantage of positively holding the engaged parts together withoutslippage until a predetermined value of torque is reached, at which timethe engaged elements are quickly released. The toggle arms ofierdecreasing resistance to opening once opening movement has started, thusinsuring that torque sufllcient to start the disengaging operation willbe enough to rapidly complete it. 7 In both cases the mechanism alsoinsures synchronized meshing of the toothed brake and clutch elements.

I claim:

1. In combination, toothed engageable elements relatively movablebetween engaged and disengaged positions, and torque means operating ona lever arm of changing length for controlling said movement, said leverarm being shortest when the elements are engaged.

2. In combination, engageable elements, and a pivoted arm retractable toengage the elements and extensible to disengagethe latter, the arm beingmovable from a retracted position of less than 45 angularity to one ofthe elements to an extended position of increased angularity thereto.

3. In combination, toothed engageable ele-- ments, at fixed reactorelement relative to which one of the engageable elements has a turningmovement, and means responsive to said turning movement for engaging anddisengaging the first mentioned elements.

4. 'In combination, engageable elements, a reactor element relative towhich one of the engageable elements' has a turning movement, and meansincluding a pivoted arm subject to compression only interposed betweenone of the engageable elements and the reactor element and responsive'tosaid turning movement for engaging and disengaging the engageableelements.

5. In combination, engageable elements, a reactor element relative towhich one of the engageable elements has a turning movement, meansresponsive to said turning movement in either direction forrespectively, engaging and disengaging the first mentioned elementsaccording to the direction of relative turning movement,

and means interposed between the first mentioned elements serving whenthe latter have become disengaged because of relative turning in onedirection to effect reengagement thereof 'upon a subsequent reversal ofthe direction of relative turning movement.

6. In combination, engageable elements, a reactor element relative towhich one of the engageable elements has a turning movement, meansresponsive to said turning movement in either direction for respectivelyengaging and disengaging the first mentioned elements accord-' ing tothe direction of relative turning movement,

and a one-way engaging device interposed between thefirst mentionedelements serving when the latter have become disengaged because ofrelative turning in one direction to efl'ect reengagement thereof upon asubsequent reversal of the direction of relative turning movement.

7. In. combination, engageable toothed elements, a reactor elementrelative to which one of the toothed elements has a limited turningmovement, means interposed between the toothed elements to effect saidturning movement, and a pivoted arm retractable upon said turningmovement to engage the elements.

8. In combination, a toothed central element, a pair of toothed platesengageable with the central element, a reactor element relative to whichsaid plates have a limited turning movement, and toggle arms pivotallyconnected between the reactor element and said plates for engaging anddisengaging the latter with the central element upon'said turningmovement.

9. In combination, engageable elements, a reactor element relative towhich one of the engageable elements has a limited turning movement,means including a pivoted arm interposed between the reactor andrelatively turnable elements for engaging the first mentioned elementsupon said movement, and means interposed between the reactor andrelatively turnable elements for reducing the shock of said engagement.

10. A connector mechanism comprising a pair of toothed engageableelements, a reactor element relative to which one of said toothedelements has a limited turning movement, and means responsive to saidturning movement and including a. pivoted arm interposed between atoothed element and the reactor element for effecting engagement of saidpair of elements without clashing the teeth. I

11. A connector mechanism comprising a pair of toothed engageableelements, a reactor elementr'elative to which one of said toothedelements has a limited turning movement, means responsive to saidturning movement and including a pivoted arm interposed between atoothed element and the reactor element for effecting engagement of saidpair of elements without clashing the teeth, and means for resilientlyurging the toothed elements into engagement.

12. A connector mechanism comprising a pair of toothed engageableelements, a reactor element relative to which one of said toothedelements has a turning movement, means responsive to said turningmovement in either direction and including. a pivoted arm interposedbetween a toothed elementand the reactor element for respectivelyeffecting engagement and disengagement of said pair of elementsaccording to the direction of relative turning movement without clashingthe teeth, and means interposed between the toothed elements servingwhen the latter have combined turning and axial movement of saidrelatively movable element.

14. A connector mechanism comprising a pair of toothed engageableelements, torque responsive means for disengaging the elements when afirst of said elements turns in one direction, and a. one-way deviceinterposed between the elements to effect reengagement thereof upontuming of said first element in the opposite direction.

15. A connector mechanism comprising a pair of engageable elements,means for mounting said elements to disengage under torque when a firstof said elements turns in one direction, and means including a one-waydevice for effecting engagement of the elements when said first elementturns in the opposite direction.

ROBERT S. TAYLOR.

